For example, when a viewer (user) views a program with a Television receiving apparatus, one of the following methods has been hitherto adopted by the user.
(1) The viewer directly views a program of a channel selected at the time when power is turned on (for example, a channel selected at the power-off time before power is turned on.
(2) The viewer selects a channel on the basis of his/her memory.
(3) The viewer carries out so-called zapping of successively switching channels to find his/her wished program.
(4) The viewer selects a program by referring to a program guide inserted in a newspaper or magazine or EPG (Electronic Program Guide) distributed through broadcast or a network.
Some Television receiving apparatuses make it possible to register favorite channels and select a program while focusing into groups of the registered channels.
When a TV program is recorded, a user uses the following methods:                (1) An operation of recording a program is directly carried out during reception of the program;        (2) The broadcast date and hour and broadcast channel of a program are indicated and a recording reservation is made;        (3) A recording reservation is made by using G codes;        (4) A program is selected from EPG and a recording reservation is made; and        (5) A Television receiving apparatus is made to search a program from EPG information on the basis of a registered keyword and automatically record the program.        
However, it needs much load and much time to zap all the programs of many channels or check programs through an EPG or the like under the present day that the digital broadcast becomes widespread and multi-channeling is advanced, and this is inefficient.
With respect to program recording, increase in capacity of recording media such as hard discs has brought television receiving apparatuses in which long-time and many programs can be recorded, and when the method of indicating programs individually and carrying out a recording operation or making a recording reservation like the prior art is used in such television receiving apparatuses, it needs much labor, and the reservation operation may be forgotten.
With respect to periodically-broadcasted programs, it is possible to register the program names or keywords and automatically make a program reservation. However, this method needs a cumbersome work of explicitly indicating the program names or the keyboards. In addition, since the preference of a viewer to programs is varied with respect to time lapse, registration contents must be changed in accordance with variation of preference.
Therefore, JP-A-2000-201303 discloses that a viewer's preference is judged from a record of program information achieved and program information is selected on the basis of the judgment result. JP-A-2000-341596 discloses that programs of plural real channels are selectively disposed along a viewer's pattern on the basis of a viewer's viewing record to create a virtual channel. JP-A-2000-155764 discloses that a viewer's preference inclination is specified to one of plural preference patterns on the basis of a viewer's program selection record to search programs which are coincident with the viewer's preference. JP-A-2000-293539 discloses that a viewer's preference is learned on the basis of a viewer's program selection record, and programs conformable with the viewer's preference are searched on the basis of the learning result. JP-A-2000-13708 discloses a program selection assist method of analyzing a viewer's viewing inclination from a viewer's program selecting operation and creating and displaying an electronic program guide based on the viewer's viewing inclination.
However, in the case of the conventional method of calculating the viewer's preference degree to a program on the basis of the viewing record of the program concerned, the preference degree to the program concerned is calculated from a program viewing time or the viewing time rate corresponding to the rate of the program viewing time to the program time length (program viewing time/program time length), and thus the preference degree is not necessarily accurately calculated in conformity with the actual situation.
More specifically, when the preference degree to the program concerned is calculated from the program viewing time, in the case of use of a calculation equation based on the assumption that the preference degree is proportional to the viewing time, the preference degree of a program is estimated to be lower as the time length of the program is shorter like the preference degree calculated when a program of 10 minutes is viewed from start to finish for 10 minutes is estimated to be equal to one sixth of the preference degree calculated when a program of 60 minutes is viewed from start to finish for 60 minutes.
On the other hand, when the preference degree to the program is calculated from the viewing time rate, in the case of use of a calculation equation based on the assumption that the preference degree is proportional to the viewing time rate, the preference degree calculated when a program of two hours and thirty minutes is viewed for one hour is equal to 0.4. Therefore, when the program time length is very long, the preference degree to the program is estimated to be low even when it is viewed for a long time. On the other hand, the preference degree calculated when a program of 20 minutes is viewed for 15 minutes is equal to 0.75. Therefore, when a short-time program is viewed for some degree of time or more, the preference degree to the program is estimated to be high even when the program is unconsciously viewed with no special purpose.
Therefore, an object of the present invention is to enable the preference degree of a viewer to contents such as broadcast programs to be accurately calculated in conformity with the actual situation.